Hamilton, Jenny Frost and Liz McLarnon performed together again at a Liverpool charity gig last month, which formed part of the city's European Capital of Culture celebrations.
Shortly afterwards, Katona complained about being left out, explaining: "I got a call from the manager asking me if I wanted to be involved. I said yes, but then I never heard anything."
Asked why Kerry was not invited to take part, Natasha replied: "Well, she left the band, didn't she? When we stopped the band, it was me, Jenny and Liz, so that's how we'll proceed in the future."
Hamilton has not spoken to Kerry for two years, but she has questioned the accuracy of the negative press reports which are written about the Iceland TV ad star.
"I see what everyone else sees and that can't be a true portrayal of her," she said.